This invention relates to border detection. In particular, organ or vessel boundaries in a patient or animal are detected.
In ultrasound imaging, detecting the borders of a vessel assists in diagnosis. Medical diagnosis by a doctor may be assisted by an image showing vessel boundaries. Volume flow or other calculations are based on the diameter of a vessel. Typically, B-mode imaging is used for identifying borders. Due to reverberation of ultrasound energy from multiple tissue layers, borders may not be well defined. For example, the border of the vessel closest to the transducer appears fuzzy or is poorly defined due to reverberations from tissue layers adjacent to the border. The border of the vessel furthest from the transducer is more sharply defined since few or no tissue layers are provided immediately adjacent the border between the border and the transducer.
To better define a border, manual border editing is provided. Using a track ball or other pointing device, a user traces where the user expects that a border is located. However, manual border editing is time-consuming and may be inaccurate. For diagnosis at different times or locations, border detection using manual techniques may be unrepeatable.
The present invention is defined by the following claims, and nothing in this section should be taken as a limitation on those claims. By way of introduction, the preferred embodiments described below include methods and systems for border detection. A border of a vessel closest to the transducer is detected using Doppler data. Since little flowing fluid is provided between the top border of the vessel and the transducer, reverberation artifacts are minimized. A border of the vessel farthest from the transducer is detected from B-mode data. Since few tissue layers are provided immediately adjacent the border farthest from the transducer between the border farthest from the transducer and the transducer, reverberation artifacts are minimized. The detected borders are used for further calculation or display. In alternate embodiments, different techniques for identifying fluid or tissue data are used, such as magnetic resonance imaging, CAT scan, x-ray or other techniques for imaging interior portions of a patient. Different ultrasound techniques may also be used, such as harmonic imaging, subharmonic imaging, multiple frequencies, coded excitation, Doppler tissue imaging or other techniques. Borders for other fluid regions in a patient may be detected, such as a heart border or other organ borders.
In a first aspect, a method for detecting a border associated with a fluid region is provided. A first portion of the border is detected with Doppler data. A second portion of the border is detected with B-mode data where the first and second portions of the border are different.
In a second aspect, a system for detecting a border associated with a fluid region of a patient is provided. A first processor is operable to detect first and second portions of the border associated with fluid and tissue data, respectively. A display is operable to display the first and second portions of the border.
In a third aspect, a method for detecting a border of a vessel is provided. The border of the vessel closer to the transducer is detected with flow data. The border of the vessel farther from the transducer is detected with tissue data.
Further aspects and advantages of the invention are discussed below in conjunction with the preferred embodiments.